Generally
1pc 0.8 mm thick valve spring shim
20 kr
1pc 0.8 mm thick valve spring shim
The valve spring shim must be under the valve spring closest to the cylinder head. Shims must be used under the valve spring if the tops are refurbished and material has been milled away from the valve seats. When the valve seat ends up deeper in the cylinder head when a valve seat is milled, shims must be placed under the valve springs to achieve the correct valve spring pressure. You can find the correct dimensions of the spring in the closed position in the workshop manual.